1. Field of Invention
The present invention relates to a valve position indicator for a buried valve and more particularly to an adjustable gear box unit of the valve position indicator for application to valves requiring a different number and/or fractions of turns between the open and shut positions thereof.
2. Prior Art
The closing or opening of underground valves of the type to which the present invention relates is generally accomplished by turning an operator shaft extending to ground level from the buried valves. Such valves may have a valve position indicator located at the ground end of the operator shaft to indicate to the worker when a valve is fully open, shut, or intermediate positions. Representative but nonexhaustive of the prior art in the area of valve position indicator is U.S. Pat. No. 3,656,504.
Heretofore, indicator plates have been permanently incorporated on the cover of the gear box unit to provide a valve open reference point and a valve shut or closed reference point. The angular spacing between the two reference points is determined by the number and/or fraction of turns required to turn the valve between its open and shut positions, each such turn referred hereinafter as a shaft revolution. Therefore, a valve position indicator having the permanently incorporated pre-set indicator plates is limited for use on valves requiring the same number of shaft revolution to open and close the same.